dt-bindings: touchscreen: fsl,imx6ul-tsc: support glitch thresold

dt-bindings: touchscreen: fsl,imx6ul-tsc: support glitch thresold

Support the debounce-delay-us property.

Drivers must convert this value to IPG clock cycles and map it to one of
the four discrete thresholds exposed by the TSC_DEBUG_MODE2 register:

  0: 8191 IPG cycles
  1: 4095 IPG cycles
  2: 2047 IPG cycles
  3: 1023 IPG cycles

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20250923143746.2857292-5-dario.binacchi@amarulasolutions.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>